According to the provisions of Article 81 of the Law of People's Republic of China (PRC) on the Prevention and Control of Air Pollution, catering service operators who discharge lampblack shall install lampblack purification facilities and keep them in normal use, or take other lampblack purification measures to make the lampblack emission reach the standard and prevent pollution to the normal living environment of nearby residents.

It is forbidden to build, rebuild or expand catering service projects that produce oil smoke, odor and waste gas in residential buildings, commercial and residential buildings and commercial floors adjacent to residential floors in commercial and residential buildings without special flues.

No unit or individual may barbecue food in the open air or provide a venue for barbecue food in the area prohibited by the local people's government.

Therefore, it stands to reason that your restaurant downstairs can be used and discharged if it is equipped with fume purification facilities and kept in normal use. If it is discharged directly without any treatment, it should not work.

If your residential building is a commercial and residential complex, it can't be discharged without a supporting planning flue.